Appropriately Inappropriate for ‘Festive Dress’

Even in a world where nothing should be taken for granted — banks, climate, Miley Cyrus — one may persuasively argue that most people are pleased to receive a party invitation. The old joke still holds: What are the two saddest words in the English language? “What party?”

But while most people may enjoy festivities, a party invitation can turn a mood ring to black with the inclusion of just one little modern-day directive: festive dress.

Perhaps you, too, are familiar with the stab of anxiety this edict produces? That little voice that cries out, “What do I wear that won’t make me look like the Joker, the Penguin or some other gleeful archenemy?” What, exactly, does festive dress mean?

“I agree, it’s pretty confusing,” said Zachary Sacks, an investment analyst in Manhattan. “I’ve read that it could mean black tie, or it could mean a tweed sport coat.”

The fashion designer Michael Bastian is more acerbic. “You need new friends, that’s what it means,” he said, laughing. “It’s so vague and confusing.”

Keep one thing in mind: Your potential host is not trying to torture you. A mood-killer for any party is bad décor, and like it or not, you are part of it. Nothing kills the fun faster than a bunch of guys who look as if they just finished moving stuff into storage, or just punched out at Dewey, Cheatem & Howe. There isn’t enough bourbon in the world to cut that ice. A good party requires a festive atmosphere, which requires guests who, however festive they really are, appear to have made an effort to look it.

One of the merits of a black-tie affair is that it offers a simple set of instructions — all you need worry about is whether your tux shirt is clean and pressed and the pants still fit. Festive dress, on the other hand, incites its own brand of fashion panic, its innocent-sounding premise being simply that you wear something special you wouldn’t ordinarily wear.

The trick comes in not under- or overshooting the mark. This requires, among other things, gauging both the setting and the host. Is the party in Lenox Hill or Vinegar Hill? At an apartment or an embassy? Is your hostess more Sally Quinn or Sally Bowles?

Your age is also a factor. The older or younger a man is, the more fun he can get away with. Who docks an 80-year-old or a newborn for style points? But a 40-year-old in a reindeer sweater may find that his name is, as they say, not on the list.

The advanced calculus required to gauge the appropriate degree of inappropriateness vexes even style veterans, though most have developed personal workarounds.

“I kind of have a uniform for office parties and Christmas parties,” Mr. Bastian said. “What I do is put on a basic tuxedo shirt with a solid navy or black tie, a tweed jacket, a red pocket square and some sort of fancy shoe or velvet slipper. I think a tuxedo shirt worn without a tuxedo is a great way to do it. It says, ‘I got the assignment, I made a little effort, but I’m still cool.’ I’ve been to parties where I’ve seen guys mess up. They’ve been dying to bust out those crazy embroidered corduroys all year long, and it doesn’t always fly. There’s still an expectation that you don’t abandon every shred of your regular style just because it’s a holiday. It’s not Halloween.”

Indeed, according to experts in such matters, part of what festive dress seems to suggest is that you steer away from anything that smacks of costume. (That includes the ugly Christmas sweater cherished by irony-loving merrymakers.)

In other words, leave the tinsel for the tree. “I see guys with gold vests and funky bow ties,” said Ralph Auriemma, design director for Paul Stuart’s Phineas Cole line, which seems made for festivity, with old-fashioned dandyish features, like colorful tweeds, peak lapels and three-piece suits. “Personally, I’m still an old-school advocate of elegant men’s wear, something with a point of view from another period of time. I’m not talking about Sherlock Holmes, though that would be festive.”

Men who overdo it are easy to spot and wince at, but there is no excuse for the many, many more who err on the side of safe. There are plenty of easy options, like a casually dressy sport coat or an elegant cardigan or pullover that’s a little too la-di-da for walking the dog. The velvet sport jacket that has come into fashion of late is perhaps the simplest and best example.

“Provided it’s well tailored,” said Madeline Weeks, fashion director for GQ, explaining that the soft, thick pile of velvet can make precise tailoring a challenge. All a man really needs, she said, is one item that shows you tried: a sharply cut silk sport coat with a dull sheen, silver leather tie or black-and-white spectator wingtips.

But make a plan, she advised: “Sometimes guys don’t think about it till it’s too late, and then run out the door in a T-shirt and a leather jacket. You don’t want to be the guy who didn’t make an effort.”

And taking a bit of trouble is, in the end, what it comes down to.

“ ‘Festive’ demands that you make an effort,” said Euan Rellie, a senior managing director at an investment bank, listing his own festive fail-safes: smoking jacket, tartan trousers, patent leather slippers (though not all at once). “Festive and sophisticated are not mutually exclusive,” he said. “It doesn’t mean ‘Pretend you’re a Christmas ornament.’ ”

While there may well be a formula for men anxious to compute exactly how much to channel the holiday spirit, it is also worth remembering that for more-daring souls, looking festive can mean flirting with decorum.

“Some people are good at dressing inappropriately,” Mr. Rellie said. “If you are confident enough, you can be underdressed when everyone is overdressed. When I was an undergraduate at Cambridge, we had the May Ball. The dress code was white tie. Rachel Gibson wore a denim miniskirt, and I fell head over heels in love with her.”

A version of this article appears in print on December 5, 2013, on page E1 of the New York edition with the headline: Appropriately Inappropriate. Order Reprints|Today's Paper|Subscribe